package com.hmdp.service.impl;

import cn.hutool.core.util.BooleanUtil;
import cn.hutool.core.util.StrUtil;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.hmdp.dto.Result;
import com.hmdp.dto.ScrollResult;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Blog;
import com.hmdp.entity.Follow;
import com.hmdp.entity.User;
import com.hmdp.mapper.BlogMapper;
import com.hmdp.service.IBlogService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IFollowService;
import com.hmdp.service.IUserService;
import com.hmdp.utils.SystemConstants;
import com.hmdp.utils.UserHolder;
import org.springframework.beans.BeanUtils;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.ZSetOperations;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.ArrayList;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class BlogServiceImpl extends ServiceImpl<BlogMapper, Blog> implements IBlogService {
    @Resource
    private IUserService userService;
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Resource
    private IFollowService followService;

    @Override
    public Result queryBlogById(Long id) {
        Blog blog = getById(id);
        if (blog == null) {
            return Result.fail("博客不存在！");
        }
        queryBlogUser(blog);
        //查询当前博客是否被点赞
        isBlogLiked(blog);
        return Result.ok(blog);
    }

    private void isBlogLiked(Blog blog) {
        //获取登录用户
        UserDTO user = UserHolder.getUser();
        if (user==null){
            //未登录,不需要查询点赞状态
            return;
        }
        Long userId= user.getId();
        //判断当前登录用户是否已经点赞过了
        String key="blog:liked:"+blog.getId();
        Double score = stringRedisTemplate.opsForZSet().score(key, userId.toString());
        blog.setIsLike(score!=null);
    }

    @Override
    public Result likeBlog(Long id) {
        //获取登录用户
        Long userId= UserHolder.getUser().getId();
        //判断当前登录用户是否已经点赞过了
        String key="blog:liked:"+id;
        Double score = stringRedisTemplate.opsForZSet().score(key, userId.toString());
        if (score==null) {
            //如果未点赞，可以点赞
            //数据库点赞数加一
            boolean isSuccess = update().setSql("liked=liked+1").eq("id", id).update();
            //保存用户到redis中去
            if (isSuccess) {
                stringRedisTemplate.opsForZSet().add(key,userId.toString(),System.currentTimeMillis());
            }
        }
        else {//如果已经点赞，则取消点赞
            //数据库点赞数减一
            boolean isSuccess = update().setSql("liked=liked-1").eq("id", id).update();
            //将取消点赞的用户从redis中移除
            //保存用户到redis中去
            if (isSuccess) {
                stringRedisTemplate.opsForZSet().remove(key,userId.toString());
            }
        }
        return Result.ok();
    }

    @Override
    public Result queryHotBlog(Integer current) {
        // 根据用户查询
        Page<Blog> page = query()
                .orderByDesc("liked")
                .page(new Page<>(current, SystemConstants.MAX_PAGE_SIZE));
        // 获取当前页数据
        List<Blog> records = page.getRecords();
        // 查询用户
        records.forEach(blog ->{
         this.queryBlogUser(blog);
         this.isBlogLiked(blog);
        });
        return Result.ok(records);
    }

    @Override
    public Result queryBlogLikes(Long id) {
        String key="blog:liked:"+id;
        UserDTO user = UserHolder.getUser();
        // 查询top5的blog,这里查出来的是带分数的，需要进行解析
        Set<String> top5 = stringRedisTemplate.opsForZSet().range(key, 0, 4);
        if (top5==null||top5.isEmpty()) {
            return Result.ok();
        }
        //解析出其中的用户id
        List<Long> ids = top5.stream().map(Long::valueOf).collect(Collectors.toList());
        //根据用户Id查询用户
        List<User> users = userService.listByIds(ids);
        BeanUtils.copyProperties(users,user);
        //返回
        return Result.ok(user);
    }

    @Override
    public Result saveBlog(Blog blog) {
        // 获取登录用户
        UserDTO user = UserHolder.getUser();
        blog.setUserId(user.getId());
        // 保存探店博文
        boolean isSuccess = save(blog);
        if (!isSuccess) {
            return Result.fail("新增笔记失败！");
        }
        //查询笔记作者的所有粉丝
        List<Follow> follows = followService.query().eq("follow_user_id", user.getId()).list();
        //推送笔记id给所有粉丝
        for (Follow follow : follows) {
            Long userId = follow.getUserId();
            String key="feed:"+userId;
            stringRedisTemplate.opsForZSet().add(key,blog.getId().toString(),System.currentTimeMillis());
        }
        // 返回id

        return Result.ok(blog.getId());
    }

    @Override
    public Result queryBlogOfFollow(Long max, Integer offset) {
        //获取当前用户
        Long userId = UserHolder.getUser().getId();
        //查询收件箱
        String key="feed:"+userId;
        Set<ZSetOperations.TypedTuple<String>> typedTuples = stringRedisTemplate.opsForZSet()
                .reverseRangeByScoreWithScores(key, 0, max, offset, 2);
        //非空判断
        if (typedTuples==null||typedTuples.isEmpty()) {
            return Result.ok();
        }
        //解析收件箱
        List<Long> ids =new ArrayList<>(typedTuples.size());
        Long minTime = 0L;
        int os =1;
        for (ZSetOperations.TypedTuple<String> typedTuple : typedTuples) {
            String blogId = typedTuple.getValue();
            ids.add(Long.valueOf(blogId));
            Long time = typedTuple.getScore().longValue();
            if (time==minTime){
                os++;
            }
            else {
                minTime=time;
                os=1;
            }

        }

        //根据id查询blog
        String idStr = StrUtil.join(",",ids);
        List<Blog> blogs = query().in("id",ids).last("ORDER BY FIELD(id,"+idStr+")").list();

        for (Blog blog : blogs) {
            queryBlogUser(blog);
            isBlogLiked(blog);
            
        }

        //封装并返回
        ScrollResult r = new ScrollResult();
        r.setList(blogs);
        r.setOffset(os);
        r.setMinTime(minTime);


        return Result.ok(r);
    }

    private void queryBlogUser(Blog blog) {
        //查询用户
        Long userId = blog.getUserId();
        User user = userService.getById(userId);
        blog.setName(user.getNickName());
        blog.setIcon(user.getIcon());
    }
}
